High breakdown voltage GaN HFET with field plate

Abstract

A novel high breakdown voltage GaN HFET with a field plate (FP GaN HFET) to form a gamma-shape gate is presented. The use of the field plate significantly reduces the field strength under the gate near the drain side. Simulation results show that the peak electric field of the device is reduced from 1.2 × 106 V/cm to 0.9 × 106 V/cm for the particular structure used. A high breakdown voltage (over 110 V) is achieved and the average ratio of BVgd over BVgs reaches a value of 2.4, compared to that of only 1.038 for a conventional GaN HFET.